Problem: $ { \left[\begin{array}{rr}{-2} & {2} \\ {3} & {-1} \\ {-1} & {-1}\end{array}\right]-\left[\begin{array}{rr}{-2} & {4} \\ {-2} & {2} \\ {-2} & {-1}\end{array}\right] = {?} } $
Solution: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{-2}-{-2} & {2}-{4} \\ {3}-{-2} & {-1}-{2} \\ {-1}-{-2} & {-1}-{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {-2} \\ {5} & {-3} \\ {1} & {0}\end{array}\right]}$